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Fencer Vulns
high 8.8

CVE-2026-53266 kev in the critical feed json

netfilter: bridge: make ebt_snat ARP rewrite writable

published 2026-06-25 4 mo ago modified 2026-09-19 51 d ago also EUVD-2026-39217

cvss
8.8
version 3.1, CNA
cisa kev
Exploited
added 2026-09-18
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

netfilter: bridge: make ebt_snat ARP rewrite writable

The ebtables SNAT target keeps the Ethernet source address rewrite behind skb_ensure_writable(skb, 0). This is intentional: at the bridge ebtables hooks the Ethernet header is addressed through skb_mac_header()/eth_hdr(), while skb->data points at the Ethernet payload. Asking skb_ensure_writable() for ETH_HLEN bytes would check the payload, not the Ethernet header, and would reintroduce the small packet regression fixed by commit 63137bc5882a.

However, the optional ARP sender hardware address rewrite is different. It writes through skb_store_bits() at an offset relative to skb->data:

skb_store_bits(skb, sizeof(struct arphdr), info->mac, ETH_ALEN)

skb_header_pointer() only safely reads the ARP header; it does not make the later sender hardware address range writable. If that range is still held in a nonlinear skb fragment backed by a splice-imported file page, skb_store_bits() maps the frag page and copies the new MAC address directly into it.

Ensure the ARP SHA range is writable before reading the ARP header and before calling skb_store_bits().

Patch / fix

cisa required action Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

  • Linux Linux 5.5, 5.9, 5.10, 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1
  • linux Debian 12 6.1.176-1
  • linux Debian 13 6.12.94-1
  • linux Debian 14 7.0.13-1

debian advisories DEBIAN-CVE-2026-53266

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-146.146
  • linux Ubuntu 26.04 LTS 7.0.0-31.31
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1066.69
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1012.12
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1070.78

ubuntu advisories UBUNTU-CVE-2026-53266

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • rv enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • perf enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • rtla enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • libperf enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • kernel-64k enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • kernel-core enterprise linux nvidia 10 6.12.0-231.20.el10nv
  • kernel-tools enterprise linux nvidia 10 6.12.0-231.20.el10nv

red hat advisories RHSA-2026:73732RHSA-2026:72059RHSA-2026:71687RHSA-2026:71657RHSA-2026:71606RHSA-2026:71601

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.243.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.243.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 5.14.21-150400.24.243.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.243.1
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.243.1
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 5.14.21-150400.24.243.1.150400.24.122.1
  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.192.2
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.192.1

suse advisories SUSE-SU-2026:4668-1SUSE-SU-2026:4667-1SUSE-SU-2026:4666-1SUSE-SU-2026:4665-1SUSE-SU-2026:4660-1SUSE-SU-2026:22742-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.36.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.36.1

opensuse advisories openSUSE-SU-2026:21388-1

  • perf AlmaLinux 10 6.12.0-211.59.1.el10_2
  • python3-perf AlmaLinux 10 6.12.0-211.59.1.el10_2
  • kernel-devel-matched AlmaLinux 10 6.12.0-211.59.1.el10_2
  • kernel-64k-devel-matched AlmaLinux 10 6.12.0-211.59.1.el10_2
  • kernel-debug-devel-matched AlmaLinux 10 6.12.0-211.59.1.el10_2
  • kernel-zfcpdump-devel-matched AlmaLinux 10 6.12.0-211.59.1.el10_2
  • kernel-64k-debug-devel-matched AlmaLinux 10 6.12.0-211.59.1.el10_2
  • kernel-rt AlmaLinux 8 4.18.0-553.143.1.rt7.484.el8_10

almalinux advisories ALSA-2026:71233ALSA-2026:39082ALSA-2026:39083ALSA-2026:36645

  • kernel Azure Linux 3.0 6.6.143.1-1

azure linux advisories AZL-90563

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-53266 updated cvss 7.5

kernel: netfilter: ebtables SNAT target writes to shared memory pages during ARP hardware address rewrite

  • Red Hat NVIDIA for RHEL 10 rv 6.12.0-231.20.el10nv, perf 6.12.0-231.20.el10nv, rtla 6.12.0-231.20.el10nv, kernel 6.12.0-231.20.el10nv, libperf 6.12.0-231.20.el10nv, kernel-64k 6.12.0-231.20.el10nv, +28 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:72059
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.143.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.143.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.143.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.143.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.143.1.el9_6
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71327
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.23.1.el9_8, perf 5.14.0-687.23.1.el9_8, rtla 5.14.0-687.23.1.el9_8, python3-perf 5.14.0-687.23.1.el9_8, kernel-devel-matched 5.14.0-687.23.1.el9_8, kernel-64k-devel-matched 5.14.0-687.23.1.el9_8, +7 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:36645
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.59.1.el10_2, perf 6.12.0-211.59.1.el10_2, rtla 6.12.0-211.59.1.el10_2, python3-perf 6.12.0-211.59.1.el10_2, kernel-devel-matched 6.12.0-211.59.1.el10_2, kernel-64k-devel-matched 6.12.0-211.59.1.el10_2, +7 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71233
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.194.1.el9_2, rtla 5.14.0-284.194.1.el9_2, kernel-devel-matched 5.14.0-284.194.1.el9_2, kernel-64k-devel-matched 5.14.0-284.194.1.el9_2, kernel-debug-devel-matched 5.14.0-284.194.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.194.1.el9_2, +5 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71601
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.152.1.el9_4, perf 5.14.0-427.152.1.el9_4, rtla 5.14.0-427.152.1.el9_4, kernel-devel-matched 5.14.0-427.152.1.el9_4, kernel-64k-devel-matched 5.14.0-427.152.1.el9_4, kernel-debug-devel-matched 5.14.0-427.152.1.el9_4, +6 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71569
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) rv 6.12.0-55.106.1.el10_0, perf 6.12.0-55.106.1.el10_0, rtla 6.12.0-55.106.1.el10_0, python3-perf 6.12.0-55.106.1.el10_0, kernel-devel-matched 6.12.0-55.106.1.el10_0, kernel-64k-devel-matched 6.12.0-55.106.1.el10_0, +7 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71326
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.143.1.el9_6, perf 5.14.0-570.143.1.el9_6, rtla 5.14.0-570.143.1.el9_6, python3-perf 5.14.0-570.143.1.el9_6, kernel-devel-matched 5.14.0-570.143.1.el9_6, kernel-64k-devel-matched 5.14.0-570.143.1.el9_6, +7 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71327
show 32 more
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.143.1.el8_10, kernel 4.18.0-553.143.1.el8_10, bpftool 4.18.0-553.143.1.el8_10, kernel-core 4.18.0-553.143.1.el8_10, kernel-tools 4.18.0-553.143.1.el8_10, python3-perf 4.18.0-553.143.1.el8_10, +20 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:39083
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.23.1.el9_8, kernel-64k 5.14.0-687.23.1.el9_8, kernel-core 5.14.0-687.23.1.el9_8, kernel-tools 5.14.0-687.23.1.el9_8, kernel-modules 5.14.0-687.23.1.el9_8, kernel-64k-core 5.14.0-687.23.1.el9_8, +29 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:36645
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.59.1.el10_2, kernel-64k 6.12.0-211.59.1.el10_2, kernel-core 6.12.0-211.59.1.el10_2, kernel-tools 6.12.0-211.59.1.el10_2, kernel-modules 6.12.0-211.59.1.el10_2, kernel-64k-core 6.12.0-211.59.1.el10_2, +30 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71233
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.209.1.el8_4, kernel 4.18.0-305.209.1.el8_4, bpftool 4.18.0-305.209.1.el8_4, kernel-core 4.18.0-305.209.1.el8_4, kernel-tools 4.18.0-305.209.1.el8_4, python3-perf 4.18.0-305.209.1.el8_4, +8 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71565
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.217.1.el8_6, kernel 4.18.0-372.217.1.el8_6, bpftool 4.18.0-372.217.1.el8_6, kernel-core 4.18.0-372.217.1.el8_6, kernel-tools 4.18.0-372.217.1.el8_6, python3-perf 4.18.0-372.217.1.el8_6, +8 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:70797
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.169.1.el8_8, kernel 4.18.0-477.169.1.el8_8, bpftool 4.18.0-477.169.1.el8_8, kernel-core 4.18.0-477.169.1.el8_8, kernel-tools 4.18.0-477.169.1.el8_8, python3-perf 4.18.0-477.169.1.el8_8, +14 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71325
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.194.1.el9_2, kernel 5.14.0-284.194.1.el9_2, kernel-64k 5.14.0-284.194.1.el9_2, kernel-core 5.14.0-284.194.1.el9_2, kernel-tools 5.14.0-284.194.1.el9_2, python3-perf 5.14.0-284.194.1.el9_2, +33 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71601
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.152.1.el9_4, kernel 5.14.0-427.152.1.el9_4, kernel-64k 5.14.0-427.152.1.el9_4, kernel-core 5.14.0-427.152.1.el9_4, kernel-tools 5.14.0-427.152.1.el9_4, python3-perf 5.14.0-427.152.1.el9_4, +33 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71569
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel 6.12.0-55.106.1.el10_0, kernel-64k 6.12.0-55.106.1.el10_0, kernel-core 6.12.0-55.106.1.el10_0, kernel-tools 6.12.0-55.106.1.el10_0, kernel-modules 6.12.0-55.106.1.el10_0, kernel-64k-core 6.12.0-55.106.1.el10_0, +27 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71326
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.143.1.el9_6, kernel-64k 5.14.0-570.143.1.el9_6, kernel-core 5.14.0-570.143.1.el9_6, kernel-tools 5.14.0-570.143.1.el9_6, kernel-modules 5.14.0-570.143.1.el9_6, kernel-64k-core 5.14.0-570.143.1.el9_6, +32 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71327
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.209.1.el8_4, kernel 4.18.0-305.209.1.el8_4, bpftool 4.18.0-305.209.1.el8_4, kernel-core 4.18.0-305.209.1.el8_4, kernel-tools 4.18.0-305.209.1.el8_4, python3-perf 4.18.0-305.209.1.el8_4, +15 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71565
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) perf 4.18.0-372.217.1.el8_6, kernel 4.18.0-372.217.1.el8_6, bpftool 4.18.0-372.217.1.el8_6, kernel-core 4.18.0-372.217.1.el8_6, kernel-tools 4.18.0-372.217.1.el8_6, python3-perf 4.18.0-372.217.1.el8_6, +15 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:70797
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.169.1.el8_8, kernel 4.18.0-477.169.1.el8_8, bpftool 4.18.0-477.169.1.el8_8, kernel-core 4.18.0-477.169.1.el8_8, kernel-tools 4.18.0-477.169.1.el8_8, python3-perf 4.18.0-477.169.1.el8_8, +8 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71325
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.23.1.el9_8
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:36645
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.59.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.59.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.59.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.59.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.59.1.el10_2
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71233
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libperf 6.12.0-55.106.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.106.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.106.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.106.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.106.1.el10_0
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71326
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.143.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.143.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.143.1.el8_10
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:39083
  • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt 3.10.0-1160.164.1.rt56.1316.el7, kernel-rt-trace 3.10.0-1160.164.1.rt56.1316.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.164.1.rt56.1316.el7
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71657
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-kvm 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-core 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-modules 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-debug-kvm 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-debug-core 4.18.0-553.143.1.rt7.484.el8_10, +4 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:39082
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.23.1.el9_8, kernel-rt-64k 5.14.0-687.23.1.el9_8, kernel-rt-core 5.14.0-687.23.1.el9_8, kernel-rt-modules 5.14.0-687.23.1.el9_8, kernel-rt-64k-core 5.14.0-687.23.1.el9_8, kernel-rt-debug-core 5.14.0-687.23.1.el9_8, +14 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:36645
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.59.1.el10_2, kernel-rt-64k 6.12.0-211.59.1.el10_2, kernel-rt-core 6.12.0-211.59.1.el10_2, kernel-rt-modules 6.12.0-211.59.1.el10_2, kernel-rt-64k-core 6.12.0-211.59.1.el10_2, kernel-rt-debug-core 6.12.0-211.59.1.el10_2, +14 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71233
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-core 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-modules 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-debug-core 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-modules-core 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-debug-modules 5.14.0-284.194.1.rt14.479.el9_2, +4 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71606
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.152.1.el9_4, kernel-rt-core 5.14.0-427.152.1.el9_4, kernel-rt-modules 5.14.0-427.152.1.el9_4, kernel-rt-debug-core 5.14.0-427.152.1.el9_4, kernel-rt-modules-core 5.14.0-427.152.1.el9_4, kernel-rt-debug-modules 5.14.0-427.152.1.el9_4, +4 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71569
  • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt 6.12.0-55.106.1.el10_0, kernel-rt-64k 6.12.0-55.106.1.el10_0, kernel-rt-core 6.12.0-55.106.1.el10_0, kernel-rt-modules 6.12.0-55.106.1.el10_0, kernel-rt-64k-core 6.12.0-55.106.1.el10_0, kernel-rt-debug-core 6.12.0-55.106.1.el10_0, +14 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71326
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.143.1.el9_6, kernel-rt-64k 5.14.0-570.143.1.el9_6, kernel-rt-core 5.14.0-570.143.1.el9_6, kernel-rt-modules 5.14.0-570.143.1.el9_6, kernel-rt-64k-core 5.14.0-570.143.1.el9_6, kernel-rt-debug-core 5.14.0-570.143.1.el9_6, +14 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71327
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.23.1.el9_8, kernel-rt-core 5.14.0-687.23.1.el9_8, kernel-rt-modules 5.14.0-687.23.1.el9_8, kernel-rt-debug-core 5.14.0-687.23.1.el9_8, kernel-rt-modules-core 5.14.0-687.23.1.el9_8, kernel-rt-debug-modules 5.14.0-687.23.1.el9_8, +4 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:36645
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.59.1.el10_2, kernel-rt-core 6.12.0-211.59.1.el10_2, kernel-rt-modules 6.12.0-211.59.1.el10_2, kernel-rt-debug-core 6.12.0-211.59.1.el10_2, kernel-rt-modules-core 6.12.0-211.59.1.el10_2, kernel-rt-debug-modules 6.12.0-211.59.1.el10_2, +4 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71233
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-kvm 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-core 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-modules 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-debug-kvm 5.14.0-284.194.1.rt14.479.el9_2, kernel-rt-debug-core 5.14.0-284.194.1.rt14.479.el9_2, +6 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71606
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.152.1.el9_4, kernel-rt-kvm 5.14.0-427.152.1.el9_4, kernel-rt-core 5.14.0-427.152.1.el9_4, kernel-rt-modules 5.14.0-427.152.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.152.1.el9_4, kernel-rt-debug-core 5.14.0-427.152.1.el9_4, +6 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71569
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt 6.12.0-55.106.1.el10_0, kernel-rt-kvm 6.12.0-55.106.1.el10_0, kernel-rt-core 6.12.0-55.106.1.el10_0, kernel-rt-modules 6.12.0-55.106.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.106.1.el10_0, kernel-rt-debug-core 6.12.0-55.106.1.el10_0, +6 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71326
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.143.1.el9_6, kernel-rt-kvm 5.14.0-570.143.1.el9_6, kernel-rt-core 5.14.0-570.143.1.el9_6, kernel-rt-modules 5.14.0-570.143.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.143.1.el9_6, kernel-rt-debug-core 5.14.0-570.143.1.el9_6, +6 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:71327
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-core 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-modules 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-debug-core 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-debug-modules 4.18.0-553.143.1.rt7.484.el8_10, kernel-rt-modules-extra 4.18.0-553.143.1.rt7.484.el8_10, +2 more
    fixed: vendor fix “Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces.” RHSA-2026:39082

4 more fixed in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. Published
  2. CISA SSVC: exploitation active
  3. Added to CISA KEV
  4. CISA patch deadline

Known exploited

Added
52 d ago
Patch by
2026-09-21 (49 d ago)
Ransomware
Not known
Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Vendor, product
Linux, Kernel
CISA name
Linux Kernel Out-of-Bounds Write Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
no
Technical impact
total
Assessed
52 d ago

Exploit prediction

0.93% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.